3,4-dihydro-2H-pyran → 3-Bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-5-carbonitrile

反応式

[Br:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([C:11]#[N:12])[CH:9]=2)[NH:4][N:3]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[O:25]1[CH:30]=[CH:29][CH2:28][CH2:27][CH2:26]1>O1CCCC1>[Br:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([C:11]#[N:12])[CH:9]=2)[N:4]([CH:26]2[CH2:27][CH2:28][CH2:29][CH2:30][O:25]2)[N:3]=1

参加物

実験手順

To a solution of 13.67 g (61.56 mmol) of 3-bromo-1H-indazole-5-carbonitrile and 2.06 g (10.8 mmol, 0.175 equiv.) of p-toluenesulfonic acid monohydrate in 247 mL of anhydrous tetrahydrofuran (THF) was added 11.2 mL (123 mmol, 2.00 equiv.) of 3,4-dihydro-2H-pyran. The mixture was refluxed under a nitrogen atmosphere for 14 h. The reaction was quenched with saturated aqueous sodium bicarbonate (sat. aq. NaHCO3). The mixture was extracted twice with EtOAc. The combined organics were washed with 2×sat. aq. NaHCO3, 1×sat. aq. NaCl, and dried over Na2SO4. Chromatography of the crude material on 200 g of silica gel using 30% EtOAc in hexanes afforded the title compound (14.34 g, 76% yield): ES-MS (m/z) 306 [M+1]+.